The formula to calculate C(n,r) is:
C(n,r)=n!r!(n−r)!
Where:
"Choose" is a term used in math to describe the operation of taking the combination of two numbers. It represents the number of ways to choose r elements from a set of n elements without regard to the order of selection.
Example 1:
Using the formula:
C(5,3)=5!3!(5−3)!=5!3!⋅2!=1206⋅2=10
The number of combinations is 10.
Example 2:
Using the formula:
C(6,2)=6!2!(6−2)!=6!2!⋅4!=7202⋅24=15
The number of combinations is 15.